Donald Kagan is engaging in one last argument. For his "farewell lecture" here at Yale on Thursday afternoon, the 80-year-old scholar of ancient Greece—whose four-volume history of the Peloponnesian War inspired comparisons to Edward Gibbon's Roman history—uncorked a biting critique of American higher education.

Not all past events have ramifications for today.

Recently I got around to reading Donald Kagan’s majestic study, The Peloponnesian War. Boy, was it majestic. Adroitly delineating the circumstances that led to the demise of the Athenian republic, Kagan makes it clear that the unnecessary conflict was one of the worst tragedies ever to befall mankind.